128723851 has 8 divisors (see below), whose sum is σ = 132804224. Its totient is φ = 124675200.

The previous prime is 128723849. The next prime is 128723863. The reversal of 128723851 is 158327821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128723851 - 2¹ = 128723849 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128723851.

It is not an unprimeable number, because it can be changed into a prime (128723831) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 451 + ... + 16051.

It is an arithmetic number, because the mean of its divisors is an integer number (16600528).

Almost surely, 2^128723851 is an apocalyptic number.

128723851 is a deficient number, since it is larger than the sum of its proper divisors (4080373).

128723851 is a wasteful number, since it uses less digits than its factorization.

128723851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15861.

The product of its digits is 26880, while the sum is 37.

The square root of 128723851 is about 11345.6533967859. The cubic root of 128723851 is about 504.9166297035.

The spelling of 128723851 in words is "one hundred twenty-eight million, seven hundred twenty-three thousand, eight hundred fifty-one".